Multi-Engine Guide
Chair flying / Engine Failure in Cruise

Engine Failure in Cruise

The unhurried version — altitude and airspeed buy you time to diagnose, so control the airplane, decide whether the engine is worth saving, then secure it and plan the arrival.

Guided rehearsal is Premium

Pre-Takeoff Engine-Failure Briefing

  1. Runway, wind, and performance — takeoff distance, accelerate-stop, and single-engine climb for today's density altitude and weight
    Light twins are not required to have a positive single-engine rate of climb at any altitude. Know before you roll whether today's airplane will climb on one.
  2. Speeds: Vr, Vyse (blue line), Vmc (red line), Vsse
  3. Failure before rotation: throttles closed, brakes, stop straight ahead
  4. Failure after liftoff with runway remaining and gear down: close the throttles and land straight ahead
    The landing gear stays selected DOWN as long as there is usable runway or overrun to land on. Gear down means continued takeoff and climb is not recommended.
  5. Failure after liftoff with the gear up and no runway remaining: pitch Vyse, mixtures/props/throttles forward, flaps up, gear up, identify, verify, feather
  6. Climb straight ahead or with shallow turns to at least 400 ft AGL before turning back; obstacles and terrain off the departure end
  7. Who flies, who touches what, and the tolerance for any simulated failure — never below Vsse
    AFH: no engine failure should ever be introduced below Vsse; if none is published, use Vyse.

Setup

  1. Yaw, roll, or a power indication goes sour — fly the airplane first“Aviate”
    Airplanes have been lost at altitude because the crew fixated on the engine problem to the detriment of flying. Cruise speed and altitude are what make this failure survivable and diagnosable — spend them deliberately.
  2. Rudder to stop the yaw, slight bank toward the operating engine, hold heading
  3. Set best speed for the situation — at least Vyse if you cannot hold altitude
    Above the single-engine absolute ceiling the airplane drifts down. Vyse minimizes the rate of altitude loss; the drift-down rate is greatest right after the failure and decreases as the single-engine ceiling is approached.

Execution

  1. Maximum available power: mixtures, propellers, throttles forward as required
    A failure at a low power setting can be deceiving — the dramatic yaw is absent. If you suspect a failure, advance both mixtures, props, and throttles significantly, to takeoff settings if necessary, so the failed engine reveals itself. You can pull the good engine back later.
  2. Identify — dead foot, dead engine“Identify”
  3. Verify — retard the suspect throttle and watch for a performance change“Verify”
    No change confirms the identification. A performance loss means partial power is still available, and an engine that still makes some power may be worth running to a safe altitude and airspeed rather than shutting down.
  4. Troubleshoot before you feather — this is the step the low-altitude drill does not have“Try to save it”
    Many power losses are fuel starvation: switch tanks. Take an orderly inventory of gauges and switches. Try carburetor heat or alternate air, another magneto, a lower power setting, a different mixture. If fuel vapor is suspected, run the boost pump. Leave the engine running if there is any doubt about needing it.
  5. Catastrophic signs → feather without further troubleshooting“Feather”
    Heavy vibration, smoke, blistering paint, or large trails of oil indicate a critical situation. Prop control fully aft; feathering may take up to 10 seconds.

Recovery

  1. Run the securing-failed-engine checklist deliberately, item by item
    Unless a fire is suspected, no undue haste. A rushed hand actuates the wrong switch. Airplane control is never sacrificed to finish a checklist.
  2. Set up the zero-sideslip climb or cruise: about 2° of bank toward the good engine, one-third to one-half ball toward it, trimmed
  3. Declare an emergency with ATC and divert to the nearest suitable airport
  4. Consider crossfeed only if prolonged single-engine flight is unavoidable — terminate it before landing
    If a suitable airport is close at hand there is no need for crossfeed. Procedures vary widely between airplanes; know the fuel system before using it. Return the operating engine to its main tank prior to landing.
  5. Plan the arrival while you still have time — weather, runway, single-engine approach and landing

ACS tolerances

  • Heading ±10°
  • Airspeed ±10 kt, never below Vyse
  • Altitude maintained ±100 ft where performance allows, otherwise a controlled drift down at Vyse
  • Correct engine identified and verified before any prop control is moved

Common errors

  • Fixating on the engine and letting heading, altitude, or airspeed go
  • Feathering a troubleshootable engine — cruise altitude bought you time to try tanks, mags, and mixture first
  • Missing a failure at low power because the yaw cue is absent
  • Rushing the securing checklist and moving the wrong control
  • Pressing on to the planned destination instead of the nearest suitable airport